Snap ring pliers



June 26, 1962 H. W. KULP SNAP RING-PLIERS 2 Sheets-Sheet 1 Filed Jan. 12, 1960 50 5 FIG-7:10-

I NVENTOR.

ATTORNEYS.

June 26, 1962 w, KULP 3,040,420

SNAP RING PLIERS Filed Jan. 12, 1960 2 Sheets-Sheet 2 INVENTOR.

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A TTORNEYS.

3,49,42 Patented June 26, 1962 3,940,420 SNAP RING PLIERS Harry W. Kuip, Lancaster, Pa, assignor to K-D Manufactnring (Iornpany, Lancaster, Pa, a corporation of Pennsylvania Filed Jan. 12, 1960, Ser. No. 1,996

10 Claims. ('Cl. 29--229) This invention relates to pliers particularly adapted for use with snap rings.

As is well known, snap rings are open-ended retaining rings which if for external use are tensioned against spreading and if for internal use are tensioned against contraction.

For handling the rings, that is for spreading external snap rings or contracting internal snap rings, the open ends of the rings are ordinarily provided with ears having holes therein for receiving the nose points of snap ring pliers.

The pliers of my present invention are particularly adapted for use with rings of different sizes having ears with apertures of difierent sizes at their open ends. In one form, the snap ring pliers of my present invention is a pliers-type tool having interchangeable nose points with different size tips adapted to be inserted in the apertures of corresponding size in the ears of an external snap ring so that the ring can be readily spread open, slipped over a shaft, and moved axially therealong to its seating groove or recess. In another form, the snap ring pliers of the present invention is a pliers-type tool having interchangeable nose points with different size tips adapted to be insorted in the apertures of corresponding size in the ears component which tends to prevent the ring from rising up the points and slipping off and which also tends to prevent snaking of the ring, i.e., twisting and excessive distortion.

The invention will be clear from a consideration of the following specification taken together with the drawing in which:

FIG. 1 is a top view of one form of pliers embodying the present invention and used for spreading external snap rings;

FIG. 2 is an end view along the line indicated IIII in FIG. 1;

FIG. 3 is a bottom view of the pliers of FIG. '1 as seen along the line IIIIII of FIG. 2.

FIG. 4 is a detailed view of the plier jaws with jaw plates removed, as seen along the line IVIV of FIG. 2;

FIG. 5 is a cross-sectional view of the pliers as seen along the line V'V of PEG. 1;

FIG. 6 is a sectional view. looking along the line VI.

VI of FIG. 1;

FIG. 7 is an exploded View of parts of the pliers of FIG. 1 showing the lever arms, the jaw plates and the lever spring;

FIG. 8 is an illustration showing a shaft over the end of which an external snap spring is being placed by the pliers of FIG. 1;

FIG. 9 is a sectional view as seen along the lines IX- IX of FIG. 8;

FIGS. 10, 11 and 12 are illustrations of some of the various forms of replaceable points which may be used in the jaws of the pliers of FIG. 1 or FIG. 13;

- FIG. 13 is a top view of another form of pliers embodying the present invention and used for contracting internal snap rings.

FIG. 14 is an exploded view showing the configuration of the lever arms of the internal snap ring pliers of FIG. 13, the other parts of the pliers not being shown since they are similar to those of the external snap ring pliers of FIG. 1 as shown in FIG. 7; and

FIG. 15 is an illustration of a shaft into which an internal snap ring is being placed by the pliers of FIG. 13.

In describing the preferred embodiments of the invention illustrated in the drawing, specific terminology has been resorted to for the sake of clarity. However, it is not the intention to be limited to the specific terms so se lected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. Referring now to the drawing, and particularly to FIGS. 1 through 10, the external snap ring pliers 36 are shown to comprise a pair of levers 32 and 34 shaped as shown in FIG. 7, each having at one end thereof a pair of spaced-apart holes for receiving rivets or the like for securing the extensions or handles 36, 33 to the levers as seen in FIG. :1. The other end of each lever 32, 34 terminates in a jaw 481B, 42. Levers 32, 34 are pivotally connected, as by a pin 44 (FIGS. 1 and 6), extending through bosses 46, 48 (FIG. 7) formed on the levers. A bias spring 5! tends to keep the handle end of the levers spread apart and the jaws closed.

As the handles 36 and 38 are brought together by the hand of the operator against the tension of spring 5t), the

studs 52, 54, in the levers 32, 34, move within the grooves or notches 56, 58 provided in the bosses 48, 46. The studs 52, 54, and notches 56, 58 limit the extent to which the jaws 4t), 42 may be spread.

In accordance with a preferred form of my present invention, each of the jaws 40, 42 is provided with a flatsided (preferably three-sided) groove 64 62, respectively, as seen in FIG. 7. A removable jaw plate 64, 56 (shown in turned-over position in FIG. 7) is provided for each jaw and adapted to be placed upon and secured to its re spective jaw, as by screws. The underside of each jaw plate 64, 66 is provided with a flat-sided (preferably three-sided) groove in a position to be coaxial and coextensive with the flat-sided (three-sided) groove in its respective jaw when the jaw plate is secured in position, whereby a fiat-sided (preferably six-sided or hexagonal) socket 73, "75, as seenin FIG. 5, is available in each jaw for receiving the flat-sided (hexagonal) shaft of one of the points of the type illustrated in FIGS. 10, 11 and 12.

In accordance with my present invention, the points 76, 78 and 80, shown in FIGS. 10, 11 and 12, each have shanks 82, 84 and 36 of fiat-sided (preferably hexagonal) cross section adapted to fit in the fiat-sided (hexagonal) sockets 73, 75 formed by each jaw and jaw plate, as just described. The use of fiat-sided (preferably hexagonal) sockets and fiat-sided (preferably hexagonal) shafts provides increased resistance to radial displacement and prevents turning of the points during spreading (or contracting) of the snap ring. This is advantageous, particularly where points with angled shafts are used, as shown in FIGS. 11 and 12.

In accordance with my present invention, each point is provided with a tip 87, 88 and 89 integral with the shank as shown in FIGS.J10, '11, 12, of circular cross'section but reverse tapered with the largest diameter being at the extremity of the tip and the smaller diameter being at the junction of the tip with the shank, thus forming the shoulders clearly visible in FIGS. 10-12. The tips 87, 88, 89 are available in different sizes corresponding to the size of the aperture in the ears of the snap ring to be handled. The shanks 82, 84, 36 are of common size.

The employment of a frusto-conical tip on the point is an important feature of my present invention. I have found that the employment of a reverse-tapered or frustoconical tip of the proper size gives, in the case of external snap ring pliers, a marked improvement in the ability of each tip to remain in its respective hole in the snap ring during spreading of the ring, and also While the ring is held spread. I have found that such tips also prevent excessive twisting or snaking of the ring. It will be seen from FIGS. 8 and 9 that, in the case of an external ring, as the jaws of the pliers are opened in the directions indicated by the arrows in FIG. 8, the tapered outer edge H, 93 of the frusto-conical tip 87 exerts on the outer edge of the hole in the snap ring 45, a force having a downward as well as an outward component, thereby tending to prevent the ring 95 from moving up on the tip 8'7, and tending to force the face of the ring against the shoulder of the point '76. Thus, in FIG. 8, the snap ring 95 is thrust against the shoulders of the point and in this manner is held firmly and substantially free of snaking on the tips of the pliers while the ring is being placed over the shaft $6 and moved axially therealong to its seating recess 97.

Referring now to FIGS. 13, 14 and 15, the internal snap ring pliers 31 of FIG. 13 are shown to comprise a pair of lever arms 33 and 35 having secured at one end thereof extensions or handles 37, 39, as seen in FIG. 13, and terminating at the other end in a pair of jaws 41, 43. Between the handle end of each lever and the jaw is a boss 47, 49 through which a pin 45 (FIG. 13) is placed and about which the levers pivot. It will be seen that when the lever arms 33, 35 are pivotally connected by the pin 45 the arms cross at the pivot point so that when the handle ends of the levers are maintained spread, as by the spring 51, the jaws 41, 43 are also spread.

As in the case of the external snap ring pliers of FIG. 1, each jaw of the internal snap ring pliers of FIG. 13 is provided with a flat-sided (three-sided) groove 61, 63, and with a jaw plate (not shown in FIG. 14) which is similar to the jaw plate shown in FIG. 7. When the jaw plate is in position, the flat-sided (three-sided) groove in the jaw plate is coaxial and coextensive with the flat-sided (three-sided) groove in the jaw, thereby forming-a flatsided (hexagonal) socket, as previously described in connection with FIGS. and 7, into which the shank of one of the points of the type shown in FIGS. 10, l1 and 12 may be inserted.

As in the case of the external snap ring pliers, when points of the types shown in FIGS. 10, 11 and 12 and of proper tip size, are used in the internal snap ring pliers of FIG. 13, and the jaws of the pliers are moved together in the directions of the arrows shown in FIG. 15, the tapered inner side of each frusto-conical tip, such as of tip 87 of FIG. 10, exerts on the inner side of the wall of each snap-ring hole a force having a downward component as well as an inward component, the downward component forcing the face of the ring against the shoulder of the point and playing an important role in tending to keep the snap ring on the tips of the pliers during contracting of the ring and also while the ring is held contracted. The action is such as also to prevent excessive twisting or snaking of the ring. Thus, as illustrated in FIG. 15, the snap ring 98 is thrust against the shoulder of the point 76 and in this manner is held firmly and substantially free of snaking on the tips of the pliers while the ring is being placed within the bore 99 of a shaft and moved axially therealong to its seating groove 100.

It will be seen from the foregoing that I have provided snap ring pliers adapted to handle a variety of sizes of snap rings and with substantially improved results. The

fact that the pliers accept interchangeable points enables the same pliers not only to handle different size rings but also permits various angle points to be interchanged in order to reach rings which would otherwise be inaccessible. And, of course, damaged or broken points can be replaced.

While the preferred embodiments of this invention have been described in some detail, it will be obvious to one skilled in the art that various modifications may be made without departing from the invention as hereinafter claimed.

Having thus described my invention, 1 claim:

1. A pliers-type tool for a snap ring, said snap ring having apertured ears at its open ends, said tool having a pair of jaws at its forward end and means at each of its jaws securely holding a replaceable point against axial and radial displacement, each of said points having a relatively long shank and relatively short tip, the sides of said shank having a plurality of flat surfaces, said tip having a circular cross section of continually increasing diameter from the inner to the outer end of the tip, the smaller diameter of said tip being less than that of said shank, thus forming a shoulder at the location where said tip joins said shank.

2. A pliers-type tool as claimed in claim 1 characterized in that the diameter of said outer end of said tip is substantially equal to that of the aperture in the ear of the snap ring.

3. A pliers-type tool as claimed in claim 1 characterized in that said shank is of hexagonal cross section.

4. A pliers-type tool as claimed in claim 2 characterized in that said shank is of hexagonal cross section.

5. A pliers-type tool as claimed in claim 4 characterized in that the shank of said point is bent at an angle.

6. A pliers-type tool for a snap ring, said snap ring having apertured ears at its open ends, said tool having a pair of jaws at its forward end each of which has an elongated flat-sided groove therein, a jaw plate for each of said jaws, said jaw plate having an elongated flat-sided groove therein, means for securing each of said jaw plates to one of the jaws of said tool such that the fiat-sided groove in said jaw plate is substantially coaxial and coextensive with the fiat-sided groove in the jaw, thereby to form an elongated flat-sided socket in the nose of each jaw of said tool, a point securely held in each socket, each of said points have a relatively long shank and a relatively short tip, said shank having a flat-sided cross section, said securing means being adapted to tighten said jaw plate against the relatively long shank of said point in said socket, the flat sides of said elongated grooves in said jaw and jaw plate pressing against the flat sides of said shank, said tip having a circular cross section of continually increasing diameter from the inner to the outer end of the tip, the smaller diameter of said tip being less than that of said shank, thus forming a shoulder at the location where said tip joins said shank.

7. A pliers-type tool as claimed in claim 6 characterized in that the diameter of the outer end of said tip is substantially equal to that of the aperture in the ear of said ring.

8. A pliers-type tool as claimed in claim 6 characterized in that said socket and said shank are hexagonal.

9. External snap ring pliers adapted for spreading an external snap ring, said snap ring having apertured ears at its open ends, said pliers comprising a pair of levers pivotally connected by a pin extending through bosses formed on the levers, said levers terminating at one end in a pair of jaws held normally closed by a biasing spring operating on said levers, each of said jaws having means for securely holding an interchangeable point against axial and radial displacement, said point having a relatively long shank and a relatively short tip, said shank having an hexagonal cross section, said tip having a frusto-conical configuration with the larger diameter at the outer end, the smaller diameter of said tip being less than that of said shank, thus forming a shoulder at the location where said tip joins said shank.

10. Internal snap ring pliers adapted for contracting 5 an internal snap ring, said snap ring having apertured cars at its open ends, said pliers comprising a pair of levers pivotally connected by a pin extending through bosses formed on the levers, said levers terminating at one end in a pair of jaws held normally open by a biasing spring operating on said levers, each of said jaws having means securely holding an interchangeable point against axial and radial displacement, said point comprising a relatively long shank and a relatively short tip, said shank having an hexagonal cross section, said tip having a frusto-conical configuration with the larger diameter at the outer end, the smaller diameter of said tip being less than that of said shank, thus forming a shoulder at the location where said tip joins said shank.

References Cited in the file of this patent UNITED STATES PATENTS 1,978,210 Lovekin Oct. 23, 1934 2,196,441 Knapp Apr. 9, 1934 2,271,064 Dolph Jan. 27, 1942 2,483,383 Heimann et al. Sept. 27, 1949 2,553,620 Yeazell May 22, 1951 2,601,547 Minock June 24, 1952 2,792,622 Wurzel May 21, 1957 

